Seasonings
Can dogs and cats eat onion?
Quick verdict for Onion: see below the answer for dogs and for cats, the symptoms of poisoning (when applicable), and what to do if your pet ate it anyway.
Toxic
Toxic
Why is this the verdict?
Onion — raw, cooked, powdered, or dehydrated — contains thiosulfates and other Allium-family compounds that damage the red blood cells of dogs and cats, causing a type of hemolytic anemia called Heinz body anemia. Unlike us, dogs and cats can't safely process these compounds, and even small, regular amounts (like leftovers from seasoned food) can cause cumulative damage.
Cats are proportionally even more sensitive than dogs to this toxicity. Onion powder, found in broths, ready-made seasonings, chips, and processed sauces, is a common and often overlooked source of poisoning.
Symptoms to watch for
Watch for these signs
- Weakness and lethargy
- Pale or yellowish gums
- Dark-colored urine (red or brown)
- Rapid breathing and elevated heart rate
- Vomiting and diarrhea
- Loss of appetite
What to do if your pet ate it anyway
See a veterinarian even if your pet seems fine — signs of anemia can take anywhere from 1 to several days to appear after ingestion. Tell the vet approximately how much and what form (raw, cooked, powdered) of onion was eaten; in recent cases, the vet may induce vomiting or give activated charcoal.
Frequently asked questions
Can dogs eat onion?
No. Onion is toxic to dogs and ingestion can be a veterinary emergency.
Can cats eat onion?
No. Onion is toxic to cats and ingestion can be a veterinary emergency.
What should I do if my pet ate onion?
See a veterinarian even if your pet seems fine — signs of anemia can take anywhere from 1 to several days to appear after ingestion. Tell the vet approximately how much and what form (raw, cooked, powdered) of onion was eaten; in recent cases, the vet may induce vomiting or give activated charcoal.
Important notice
This content is educational and does not replace a veterinary evaluation. Every animal reacts differently depending on weight, age, breed, and health history — when in doubt, consult a veterinarian or an animal poison control center.